Transmutex is a Franco-Swiss startup, close to CERN, developing a very special “TMX-START” reactor: being subcritical, neutrons would be supplied by a particle gas pedal, which would transmute fertile fuel(thorium) into fissile fuel(uranium 233). These fast neutrons would also enable the transmutation of more problematic atoms (e.g. americium), radically limiting the amount of radioactive waste produced.
Transmutex technology: absolute safety?
The Transmutex reactor, known as“TMX-START” (Transmutex Subcritical Transmutation Accelerated Reactor with Thorium) is “subcritical”: there is no self-sustaining chain reaction. If the external supply of neutrons ceases, the reaction stops almost immediately: in 2ms according to Transmutex. How, one might ask, could an accident occur in this context?
But where do the electrons come from? This is the esoteric part of the project: they come from a particle gas pedal (an 800MeV – 5mA, 40x60m cyclotron, inspired by the MEGAPIE project)! As the protons approach the speed of light, they will collide with the metal targets inside, producing neutrons by “spallation”. Contrary to popular belief, this type of equipment is not uncommon: there are an estimated 30,000 particle gas pedals worldwide, mainly for medical purposes. In this case, the process is called “Accelerator Driven System” (ADS).
The fuel is thorium (fertile), which is transformed into uranium 233 (fissile) before fission. The neutrons would be “fast” (and not slow or thermal), enabling transmutation and drastically limiting the waste produced (on the order of a few kilos instead of tons), with a lifespan several thousand times shorter.(source) They could even transmute and use heavier atoms, such as plutonium, neptunium or americium. The coolant is a molten lead-bismuth alloy. The energy price (LCOE) is estimated at less than $70/MWh.(source)
The reactor is not strictly speaking a 4th-generation reactor, as it is not on the list, but it looks like it could be.
The reactor’s target power output is currently 100 MW.
Transmutex progress and financing
Transmutex was co-founded in 2019 by Franklin Servan-Schreiber (CEO) and Federico Carminati (CSO) in Geneva. The latter worked at CERN with Carlo Rubbia, who developed the idea behind START in the 90s. The project is advised by a number of top-level scientists, many of whom have worked at CERN.
Transmutex would be a partner not only of CERN, but also of
- argonne National Laboratory, for fuel and coolant aspects
- eNEA, for cyclotron targets and core design
- institut Paul Scherrer, for the cyclotron and target
- TheCzech CVR Institute for experimental validation
- Alcen, which designed the hot cell circuits for Astrid, for robotization and hot cells
They would have developed advanced digital tools to model and simulate their system.
A first round of funding(15 million Swiss francs according to the video) was closed in November 2021 with venture capital fund UVC.
The 300MW pilot plant is valued at 2 billion Swiss francs (~€). They hope to design it before 2030.
FAQ
Where is Transmutex headquartered?
Transmutex is based in Geneva, Switzerland.
How does transmutation help treat nuclear waste?
Fast neutron bombardment can transform long-lived, high-intensity radionuclides into shorter-lived, less radioactive atoms.